Updateappend the same log file in S3, no chunking by time

[humpalu]

Hi,
I would like to upload the logs to S3. Here is my config for the upload

<source>
  @type tail
  path /var/log/nginx/SERVER_NAME_PLACEHOLDER.access.log 
  pos_file /var/log/td-agent/servername_access.pos
  <parse>
    @type apache2
  </parse>
  tag "s3.access.#{Socket.gethostname}"
</source>

<match s3.*.*>
  @type s3
  aws_key_id XXX
  aws_sec_key XXX
  s3_region eu-central-1
  s3_bucket my-logs
  store_as txt
  path "logs/${tag}/"

  <buffer tag>
    @type file
    path /var/log/td-agent/s3
    timekey 3600
    timekey_wait 10m
    chunk_limit_size 256m
  </buffer>

#  time_slice_format %Y%m%d%H
</match>

But I dont want to make chunks. I would like to make only access.log every day and append the new content to that file.
Is that possible? I was thinking to upload the log file only one time a day but if the server crashes I will lose the all logs.